The field of the invention is pneumatic control apparatus, and the invention relates more particularly to push buttons which may be operated by hand, and or foot, and which cause air or other fluids to move into and out of the port of the push button assembly.
Common approaches for operating air-controlled valves include the use of bellows or a piston and cylinder arrangement, but such approaches frequently require maintenance if not carefully operated. For applications which must withstand abuse such as when used to control water valves in public restrooms, such piston or bellows approaches do not have sufficient durability and reliability for practical use.